The present invention relates to a method and apparatus for fracturing a subterranean formation, and more particularly, to a low cost method and apparatus for fracturing a subterranean formation with a sand suspension.
The ordinary flow of hydrocarbons into a well may not be rapid enough to make a drilling operation commercially viable. Therefore, stimulating a subterranean formation can be helpful and necessary to facilitate the conductivity of hydrocarbons through a subterranean formation and into a drilled wellbore or hole. One means of stimulating hydrocarbon flow is through fracturing a subterranean formation.
A number of solutions have been proposed to fracture a subterranean formation. One solution proposes using dry sand that is either dumped from a truck or transferred from a storage device via a conveyor belt into a mixing device where it is mixed with a fracture fluid and liquid additives. The mixing device then discharges the mixture of sand and fracture fluid into one or more pumps that transfer the fluid downhole. This solution, however, can be very resource intensive as the sand, fracture fluid, and liquid additives require their own storage devices and pumps. In addition, a separate blending device is required to combine the sand and fluids. In some embodiments, this solution can require up to twenty-seven large pieces of equipment. This solution is also sometimes unable to maintain consistency in the composition of the fracture fluid. The composition can therefore be highly variable and can lead to unpredictable fracturing results.
Another solution for fracturing a subterranean formation uses a mixture of sand and fluid contained in a storage device that is constantly agitated to keep the sand suspended in the fluid. The storage device discharges the agitated mixture into a blending device where it can be blended with liquid additives and other fluids, which themselves require storage devices. The blending device outputs the sand fluid into one or more pumps that transfer the fluid downhole to accomplish fracturing the subterranean formation. This solution, however, is also resource intensive and requires an extremely expensive and complex piece of equipment in the agitating storage device. This solution may also not maintain consistency in the composition of the fracture fluid and can therefore lead to unpredictable fracturing results.